Eur. Phys. J. D (2014) 68: 360
https://doi.org/10.1140/epjd/e2014-50312-3

Regular Article

Radiation pressure force on cold rubidium atoms due to excitation to a non-cooling hyperfine level

¹ Institute of Physics, Bijenička cesta 46, 10000 Zagreb, Croatia
² Department of Physics, University of Zagreb, Bijenička cesta 32, 10002 Zagreb, Croatia

^a e-mail: ticijana@ifs.hr

Received: 18 April 2014
Received in final form: 28 July 2014
Published online: 1 December 2014

Abstract

We study the radiation pressure force exerted on cold ⁸⁷Rb atoms captured in a magneto-optical trap (MOT) due to resonant excitation of atoms into the non-cooling 5P_{1 / 2}(F_e = 2) hyperfine level. We measure the fractional excited population for different MOT parameters such as cooling laser detuning and power, and empirically test the applicability of the Optical Bloch Equations for describing cold atoms in the MOT. We use the effective saturation intensity parameter which enables simple calculation of the fractional excited state population in a multi-level system using a two-level model, and apply it for the radiative force modeling. This approach provides a valuable tool for optical manipulation experiments.